The present invention pertains to a straight sewing machine and more particularly to a device for such machines for retaining the free end of a chain of stitches until the beginning of a new seam so as to incorporate the free end of the chain into the new seam. A device for retaining a chain of stitches at the beginning of the seam is well known in the case of sewing machines adapted to produce a zig-zag or overcasting stitch and hence in machines in which the stitches are formed transversely with respect to the sewing axis.
In these types of machines the chain of stitches is readily incorporated in the succeeding seam without precise alignment with the sewing axis for the width of the seam is substantially wider than that of the chain. Additionally in these types of machines the chain is located close to the workpiece support surface and is thus incorporated in the stitching beneath the workpiece per se. In the case in point, i.e., of a straight sewing machine in which the chain must be incorporated in a seam having the same dimensions as the chain, the arrangement employed on zig-zag or overcasting machines cannot be utilized for it is not possible to provide positive alignment of the chain with the needle since it is covered by the workpiece and cannot be controlled when it is released from the chain retention device.
An object of the present invention is that of providing a device for the positive control of the chain of stitches at the beginning of a seam in straight sewing machines so as to incorporate the chain into said seam.
To attain this object, the technical problem which the present invention is adapted to solve is that of retaining a chain of stitches in such a way that it intersects the needle axis, and of maintaining it in this position along its entire length so that it is completely incorporated in the stitching being formed.